Question

Which of the following condition(s) is/are necessary for total internal reflection to take place at the boundary of two different media?

• A. The angle of incidence should be greater than the critical angle.
• B. Light ray passes from optically rarer medium to optically denser medium.
• C. The angle of incidence should be less than critical angle.
• D. Light ray passes from optically denser medium to optically rarer medium.

Answer 1

Answer: (A), (D)

The correct options are
A The angle of incidence should be greater than the critical angle.
D Light ray passes from optically denser medium to optically rarer medium.

When a ray of light passes from a medium of greater optical density to that of a lower optical density at an angle of incidence greater than the critical angle, the ray is reflected back into the same medium. This phenoenon is known as Total Internal Reflection.